Chloroalkyl piperazine and nitrogen mustard porphyrins: synthesis and anticancer activity

Fifteen new chloroalkyl piperazine and nitrogen mustard porphyrins have been synthesized by the direct condensation of chloroalkyl piperazine, nitrogen mustard benzaldehyde, and pyrrole. Each porphyrin bears 1-4 chloroalkyl piperazine or nitrogen mustard moieties, which have been used as drugs. The Lindsey method was modified to synthesize chloroalkyl piperazine and nitrogen mustard porphyrins. To successfully synthesize chloroalkyl piperazine and nitrogen mustard porphyrins, catalyst acidity was proved to be the key factor, while the ratio of pyrrole to aldehyde had great influence on product yield. The synthetic chloroalkyl piperazine and nitrogen mustard porphyrins were characterized by elementary analysis, MS, (1)H NMR, IR, and UV-vis. Their anticancer activity to bel-7404 liver cancer cells was tested by the MTT assay. Most of the synthetic porphyrins had good anticancer activity toward bel-7404 liver cancer cells in the absence of light. These compounds might be potential anticancer medicines.     

Novel benzoyl nitrogen mustard derivatives of pyrazole analogues of distamycin A: synthesis and antileukemic activity

The design and synthesis of novel benzoic acid mustard (BAM) derivatives of distamycin A bearing one or more pyrazole rings replacing the pyrrole rings of the latter are described. In vitro and in vivo activities against L1210 leukemia are reported and discussed. Some of these compounds show an activity profile comparable to tallimustine 1. All the compounds bearing the pyrazole ring close to the BAM moiety show reduced cytotoxicity in comparison to derivatives characterized by the BAM linked to a pyrrole: the same effect has not been observed when occurring at the amidine terminus of the oligopeptidic frame.     

Synthesis, DNA binding, topoisomerases inhibition and cytotoxic properties of 4-arylcarboxamidopyrrolo-2-carboxyanilides

Three 4-arylcarboxamidopyrrolo-2-carboxyanilides bearing different substituents on the pyrrole nitrogen were synthesized and evaluated for their capacities to bind to specific sequences within the minor groove of DNA and to inhibit human topoisomerases I and II in vitro. The cytotoxicity of the drugs correlates with their DNA binding affinities. The two drugs bearing a N-methyl or N-benzyl pyrrole stabilize topoisomerase I-DNA complexes.     

DNA binding ligands targeting drug-resistant Gram-positive bacteria. Part 2: C-terminal benzimidazoles and derivatives

The synthesis and in vitro potency of DNA minor-groove binding antibacterials lacking the C-terminal amide bond are described. The crescent shaped molecules bear the positively charged amino group at an internal pyrrole unit instead of the C-terminus. Three structural parameters were investigated: the N-terminal unit, the internal amino group, and the C-terminal ring system. Several compounds demonstrated good in vitro potency against various Gram-positive bacteria and some molecules were moderately active against Escherichia coli, a representative Gram-negative strain.     

Synthesis And Biological Evaluation Of Nitrogen Mustard Derivatives Of Purine Bases

This paper deals with the synthesis of nitrogen mustard analogs, derivatives of purine bases. Alkylation in position N-9 and diethanolamine fixation on position 6 were managed by microwave irradiations. Chlorination of these dihydroxylated intermediates led to a cyclization, giving tricyclic purine base analogs bearing a chloroethyl chain. Finally, MTT assays on obtained compounds do not show cytotoxicity on four different cancer cell lines.     

Benzoyl nitrogen mustard derivatives of benzoheterocyclic analogues of netropsin: synthesis and biological activity

Synthesis, DNA binding properties and biological activity of a series of bis-benzoheterocycle derivatives 5-11, structurally related to the natural dipyrrole antitumor agent netropsin, and tethered to a benzoyl nitrogen mustard (BAM) as alkylating moiety is reported and structure-activity relationships determined. These compounds 5-11 have been evaluated for sequence selective alkylating properties and cytotoxicity against murine L1210 and human K562 leukaemia cells. Using as target sequence a portion of the long terminal repeat of the type-1 human immunodeficiency virus, we found that these compounds induce similar patterns of DNA fragmentation. In addition, the results obtained indicate that all synthesized compounds retain a good antiproliferative activity in the submicromolar range, and generally are more active against L1210 than K562 cells. With respect to both these cell lines, compounds 6, 7, 10 and 11 showed the greatest potency, ranging from 0.3 to 1 microM, while compounds 8 and 9 exhibit the lowest activity (IC(50)=2-12 microM). Among compounds 5-11, the derivative 11 was found to be the most potent member of this class and it is 5 and 10-fold less active than the bis-pyrrole counterpart 2 against K562 and L1210 cell lines, respectively. For compound 11, the substitution of the C-terminus benzofurane with N-methylindole and indole (to give the compounds 5 and 6, respectively) led to a decrease in cytotoxicity, which is more evident against the K562 cell line. Finally, differences were found among compounds 5-11 in induction of K562 differentiation. Some of them (compounds 7, 8 and 9) are potent inducers of erythroid differentiation of K562 cells, and could be proposed for differentiation anti-cancer therapy.     

The alkylation of hemoglobin S by nitrogen mustard. High resolution proton nuclear magnetic resonance studies.

Sickle cell hemoglobin (Hb S) treated with nitrogen mustard (bis(beta-chloroethyl)methylamine hydrochloride) gives two reaction products, one labile and one stable. After dialysis against buffer solution, the remaining stable product is found to inhibit the polymerization of deoxyhemoglobin S. High resolution proton nuclear magnetic resonance has been used to study the structure and function of this stable product and to investigate the nature of the binding sites of nitrogen mustard to the hemoglobin molecule. The NMR results suggest that the nitrogen mustard treatment of Hb S does not alter the heme environment or the subunit interfaces of the hemoglobin molecule. Moreover, the NMR spectra have also shown that the nitrogen mustard reacts with the beta2 histidines of the hemoglobin molecule and have suggested that several other surface amino acid residues of the hemoglobin molecule are also affected by the nitrogen mustard alkylation. These NMR findings are in good agreement with the data obtained from biochemical studies of nitrogen mustard-treated Hb S. The NMR spectra also indicate that nornitrogen mustard (which is also effective in inhibiting sickling) binds with the hemoglobin molecule in a manner identical with nitrogen mustard. Sulfur mustard, on the other hand, produces no observable changes in the aromatic proton resonances, which is consistent with the fact that it does not inhibit the polymerization of deoxy-Hb S.     

Effect of Dexamethasone and Nitrogen Mustard on the Production of Rheumatoid Factor in Rheumatoid Arthritis

The effect of dexamethasone and nitrogen mustard on the production of rheumatoid factor, as measured by sensitized sheep cell and latex agglutination tests, was studied in 19 patients with classical rheumatoid arthritis. Dexamethasone was given orally in a daily dose of 6-8 mg. which was slowly reduced after a two-week period. Nitrogen mustard was infused in the usual therapeutic dose of 0.3 mg./kg. The level of circulating rheumatoid factor decreased, following administration of each agent, after a latent period of 10 days. The effect was most marked at around 30 days. Dexamethasone was more potent than nitrogen mustard. Both drugs together caused transient disappearance of rheumatoid factor in one patient.It is concluded that dexamethasone and nitrogen mustard have the capacity to suppress the formation of the macroglobulins associated with rheumatoid arthritis.     

Synthesis of Lipid Derivatives of Pyrrole Polyamide and Their Biological Activity

Novel fatty acyl and phospholipid derivatives of pyrrole polyamide were synthesized. Their cytotoxicity against a cancer cell line of MT-4 cells and those infected by human immunodeficiency virus (HIV) was examined. Although no anti-HIV activity was found, their cytotoxicitty against the cancer cells was significantly enhanced by introducing a lipophilic group into the pyrrole polyamide.     

The induction of aneuploidy by nitrogen mustard in a human lymphoblastoid cell line

We report that the presence of an extra Y chromosome can be used as a marker for the induction of aneuploidy (mitotic non-disjunction) in a human lymphoblastoid cell line. This endpoint is easily visualized in metaphase chromosome preparations after staining with quinacrine mustard. The induction of cells with two Y chromosomes by nitrogen mustard (NM) was examined. Exposure to 150 ng/ml nitrogen mustard induced a 6-fold increase in aneuploid frequency relative to untreated control levels; maximal induction of aneuploidy was observed 2 days after treatment. Lower concentrations of nitrogen mustard (36 and 75 ng/ml) induced smaller increases in aneuploid frequency, with maximal induction observed 1 day after treatment. This system has the potential to be used as an assay for the induction of aneuploidy in cultured human cells.     

Synthesis of lipid derivatives of pyrrole polyamide and their biological activity

Novel fatty acyl and phospholipid derivatives of pyrrole polyamide were synthesized. Their cytotoxicity against a cancer cell line of MT-4 cells and those infected by human immunodeficiency virus (HIV) was examined. Although no anti-HIV activity was found, their cytotoxicitty against the cancer cells was significantly enhanced by introducing a lipophilic group into the pyrrole polyamide.     

X-Rays and Nitrogen Mustard: Independent Action in Chinese Hamster Cells

We have studied the combined effects of X-irradiation and nitrogen mustard treatment on the colony-forming ability of Chinese hamster cells. In contrast to X-irradiation, nitrogen mustard acting by itself yields an exponential dose-effect relationship. Moreover, whether delivered in immediate sequence or after varying intervals, nitrogen mustard treatment does not affect radiation survival and vice versa. These results, plus the lack of any indication of the repair of sublethal nitrogen mustard damage, are consistent with independent but different modes of action at the same site(s), or action at different sites.     

Kinetic Data on the Inhibition of High-affinity Choline Transport into Rat Forebrain Synaptosomes by Choline-like Compounds and Nitrogen Mustard Analogues

Abstract: A series of choline analogues and nitrogen mustard derivatives were evaluated as inhibitors of high-affinity transport of choline in rat forebrain synaptosomes. When synaptosomes were preincubated for 10 min with choline mustard aziridinium ion, monoethylcholine and monoethylcholine mustard aziridinium ion, the agents appeared to be equipotent as inhibitors of high-affinity uptake (K_i=2.63, 3.15 and 2.72 μm , respectively). Acetylcholine mustard aziridinium ion was less potent than these compounds (K_i= 27.8 μm ), but it was more potent than ethoxycholine and ethoxycholine mustard aziridinium ion (K_i= 500 and 403 μm ) as a blocker of choline transport. From study with these compounds it was concluded that the high-affinity choline transport mechanism shows specificity for hydroxylated compounds over those in which the same hydroxyl has been acetylated (10-fold) and that the carbonyl oxygen of the acetylated analogues is important, as its removal (to form the ethylether derivative) decreased affinity another 20-fold. The presence of an aziridinium ring on the quaternary nitrogen in place of two methyl groups did not affect the blocking of transport at 10 min of inhibitor preincubation and replacement of a methyl group on the nitrogen by an ethyl group did not alter affinity for the high-affinity carrier. The aziridinium ring on the nitrogen of the mustard analogues was important, however, in determining the extent of reversibility of the binding of these agents to the carrier protein. Choline transport was not restored by washing synaptosomes that were incubated with choline mustard aziridinium ion or monoethylcholine mustard aziridinium ion, but was readily obtained in washed synaptosomes preincubated with monoethylcholine, hemicholinium-3, or pyrrolcholine. The results indicate that the mustard analogues may be potent alkylators of the high-affinity choline carrier and thus, useful agents in monitoring acetylcholine turnover in systems where the carrier is blocked.     

DNA sequence selectivity of guanine-N7 alkylation by nitrogen mustards.

Nitrogen mustards alkylate DNA primarily at the N7 position of guanine. Using an approach analogous to that of the Maxam-Gilbert procedure for DNA sequence analysis, we have examined the relative frequencies of alkylation for a number of nitrogen mustards at different guanine-N7 sites on a DNA fragment of known sequence. Most nitrogen mustards were found to have similar patterns of alkylation, with the sites of greatest alkylation being runs of contiguous guanines, and relatively weak alkylation at isolated guanines. Uracil mustard and quinacrine mustard, however, were found to have uniquely enhanced reaction with at least some 5'-PyGCC-3' and 5'-GT-3' sequences, respectively. In addition, quinacrine mustard showed a greater reaction at runs of contiguous guanines than did other nitrogen mustards, whereas uracil mustard showed little preference for these sequences. A comparison of the sequence-dependent variations of molecular electrostatic potential at the N7-position of guanine with the sequence dependent variations of alkylation intensity for mechlorethamine and L-phenylalanine mustard showed a good correlation in some regions of the DNA, but not others. It is concluded that electrostatic interactions may contribute strongly to the reaction rates of cationic compounds such as the reactive aziridinium species of nitrogen mustards, but that other sequence selectivities can be introduced in different nitrogen mustard derivatives.     

Amphotericin B (Fungizone®) enhancement of nitrogen mustard uptake by human tumor cells

In HT29 human colon carcinoma cells, amphotericin B at doses above 120μg/ml increased nitrogen mustard uptake, and this was due to an increase in the apparent V_max without a change in the apparent K_m. Longer incubations (24 to 48 hr) of ascites fluid human ovarian carcinoma cells or SKMES-1 human epidermoid carcinoma cells with amphotericin B 4μg/ml enhanced the uptake of nitrogen mustard to a greater degree than that observed when cells were incubated for only 30 min. Therefore, amphotericin B can enhance nitrogen mustard by human tumor cell lines and by fresh human tumor cells.     

Chemical probes of a trisubstituted pyrrole to identify its protein target(s) in Plasmodium sporozoites

Malaria is a disease that has a major impact in many developing nations, especially on the African continent. There is a need to develop new therapeutics and prophylactic treatments against it. A trisubstituted pyrrole was recently found to inhibit infection of mammalian hepatocytes by Plasmodium sporozoites, but the target of this agent is not known. In this study trisubstituted pyrrole derivatives with different substituents on a piperidinyl nitrogen were prepared. We determined if modifications of the piperidinyl nitrogen would accommodate a drug–biotin linking strategy for affinity purification of the trisubstituted pyrrole’s target protein(s).     

Enhanced potentiation of cisplatin cytotoxicity in human ovarian carcinoma cells by prolonged glutathione depletion

We have determined the effect of extended glutathione (GSH) depletion on cis-diamminedichloroplatinum(II) (DDP) cytotoxicity in parent and DDP-resistant human ovarian carcinoma cells. Cells were exposed to 50 microM buthionine sulfoximine (BSO) for 48 h and exposed to DDP for the last 24 h of this time. This treatment protocol sensitized 2008 cells to DDP. The dose modification factor (DMF) defined as IC50 control cells/IC50 GSH depleted cells was 1.6 +/- 0.5 (N = 9). DDP-resistant cells selected by acute, high dose DDP exposure were also sensitized by this treatment; the DMF in the 3-6-fold resistant 2008/DDP cells was 2.4 +/- 1.2 (N = 9). The sensitization was not significantly greater in the resistant cells than in the parent cells (P greater than 0.05). When the rebound of GSH following BSO exposure was reexamined, the GSH levels were found to rise rapidly following trypsinizing and plating. BSO treatment following DDP exposure had no effect on DDP cytotoxicity in 2008 and 2008/DDP cells. These results indicate that simply depleting GSH prior to DDP exposure is not sufficient for sensitizing these cells to DDP. In contrast to the potentiation of nitrogen mustard cytotoxicity, exposure to GSH depletion must be maintained during DDP treatment for enhancement of DDP cytotoxicity to occur.     

Effects of (2 Chloro-Ethyl) Trimethlammonium Chloride on Plant Growth, Leaf Area, and Net Assimilation Rate

Both under glasshouse conditions and in a constant environmentwith light from fluorescent tubes, mustard plants' treatmentwith (2 chloro-ethyl) trimethylammonium chloride (CCC) respondedby an increase in total leaf area. In the glasshouse the increasewas due to the production of more lateral leaves, and in thegrowth chambers to the enlargement of stem leaves, since lateralbranches did not form. Despite the increase in area, the netassimilation rate fell; this may be attributable to an effectof CCC on the photosynthetic mechanism or to an increase inthe mutual shading of leaves, but it is more probable that theinhibition of stem growth also caused by CCC decreases the demandfor photosynthate and leaves photosynthesise less. The leafarea of mustard (a long-day plant) is increased also by short-daytreatment, and here again there is a concomitant shorteningof the stem. Chlorophyll content, both per leaf and per unit area, and totaldry matter per unit area, were increased in tobacco plants grownin culture solutions containing CCC. The treatment affectedthe distribution of nitrogen, increasing the amount per leafand decreasing it per stem.     

Synthesis, characterization and antitumor activity of copper(II) complex with nicotinamido-4-bis(2-chloroethyl)aminobenzaldimine.

Nicotinamido-4-bis(2-chloroethyl)aminobenzaldimine (NBAB) was synthesized and characterized by elemental analysis, IR and 1H NMR spectra. The complex of Cu(NBAB)2(NO3)2 was prepared in ethanol and characterized by elemental analysis, conductivity, cyclic voltammetry, IR, UV-Vis, fluorescence, CD and EPR spectra. The characteristic data suggest that the complex has an elongated octahedral structure, and NBAB behaves as bidentate in the keto form. The antitumor activities of NBAB and the complex against L1210 murine leukemia and K562 were investigated with both the MTT method and the colony formation test. The results in vitro indicate that antitumor activities of NBAB are superior to 2,2'-chlorodiethylamine hydrochloride (nitrogen mustard) for L1210, and inferior to nitrogen mustard for K562, but the antitumor activities of the complex for both cell lines are superior to nitrogen mustard.